and for Berge's lemma, which states that a matching M in a graph G is maximum if and only if there is in G no augmenting path with respect to M. Art In addition to mathematics, Claude Berge enjoyed literature, sculpture, and art. Berge co-founded the French literary group Oulipo with novelists and other mathematicians in 1960 to create new forms of literature. In this association, he wrote a murder mystery based on a mathematical theorem: Who killed the Duke of Densmore? In an adaptation of this story, the Duke of Densmore is killed by an explosion. Ten years later, Sherlock Holmes and Dr. Watson are called to investigate this unsolved case. Using the testimonies of the Duke's seven ex-wives and his knowledge of interval graphs, Holmes is able to determine which one made multiple visits to the Duke and was able to plant the bomb. Awards and honors Berge won the EURO Gold Medal from the Association of European Operational Research Societies in 1989, and (with Ronald Graham) the inaugural Euler Medal from the Institute of Combinatorics and its Applications in 1993. Selected publications Major mathematical works (Note: Rough English translation in parentheses) Théorie générale des jeux à n personnes (General theory of games for n players), 1957, trans. in Russian, 1961 Théorie des graphes et ses applications, Wiley, 1958, trans. English, Russian, Spanish, Romanian, Chinese. English translation: The Theory of Graphs and its Applications, Wiley, 1964 Espaces topologiques, fonctions multivoques, 1959, trans. in English, 1963. English translation Topological Spaces: Including a Treatment of Multi-Valued Functions, Vector Spaces and Convexity, Dover Books, 2010. Programmes, jeux et réseaux de transport, with A. Ghouila-Houri, Wiley, 1962, trans. English, Spanish, German, Chinese. English Translation: Programming, Games and Transportation Networks, Wiley, 1965 Graphes parfaits (Perfect graphs), 1963 Principes de Combinatoire, Wiley, 1968. English translation: Principles of Combinatorics, Academic Press, 1971 Graphes et Hypergraphes, in 1969 and 1970, trans. in English, Japanese. English translation: Graphs and Hypergraphs, North-Holland Publishing Company, 1973. Hypergraphes. Combinatoires des ensembles finis (Hypergraphs. Combinatorial finite sets), Gauthier-Villars, 1987, trans. English Literary work Sculptures Multipètres, 1961 La Reine Aztèque (Aztec Queen), 1983 Qui a tué le Duc de Densmore? (Who Killed the Duke of Densmore?) 1994 Raymond Queneau et la combinatoire (Raymond Queneau and combinatorics), 1997 References External links Mathematical works of Claude Berge Claude Berge page at University of Montreal by Gena Hahn Obituaryby Srinivas Bhogle Obituary by Václav Chvátal